Improvement in machines for picking millstones



PATENT OEEICE.,

STEPHEN A. BELL, OF NEWTOWN, OHIO.

IMPROVEMENT IN MACHINES FOR PICKING MILLSTONES.

Specification forming part of Letters Patent No. 120,181, dated October 24, 1871.

To all whom it may concern:

Be it known that I, STEPHEN A. BELL, of Newtown, Hamilton county, State of Ohio, have invented a certain new and useful Improvement in Millstone Picking Device, of which the following is a specification:

My invention consists of a portable device for performing the operation called cracking7 on a millstone, the device being so constructed that the pick is directed to crack in a right line and fed so as to make the lines of cracking parallel to each other, the device also being such that the pick,no matter how long or short, can strike the stone perpendicularly.

Figure lis a plan of my improved millstone picker. Fig. 2 is a side elevation of the same partly in section.

The instrument is designed to rest upon the millstone in the operation of cracking, and the frame of it, A, combines in its construction a scat, B, for the operator. The sides of the frame are iitted with slides C, which move out and in from the operator throughout the entire range ofthe series of lines to be cracked between two leading furrows on the millstone. The slides C form journal-bearings for the shaft -D which carries the picket. Racks E are fitted to the interior of the frame into which the pinions F upon shaft D mesh, the pinions and racks serving to retain the shaft in a line at right angles to the slides, and also to feed the pick forward or backward for the formation of the successive cracks. The feeding is accomplished by means of the ratchet-wheel G, the pawl H of which retains it in any position to which it may be adj usted. For backing the slides quickly the pawl H may be swiveled on screw J, out of connection with the ratchet-wheel G. The picker-arm consists of two bars, K K', the inner end of K swivcling upon the shaft D andthe outer end .of bar K being fitted with the clamp k k la' k' for holding the pick L. The screws 7c' k' of the clamp enable the employment of different sizes of picks. The

arms K K' are connected together in the middle by a joint, M, which, by the provision of the screw N, can be so tightened that a stiff arm is presented from the clamp to the shaft D. 'Vhen a pick is placed in the clamp the joint M is slackened and so adjusted that the pick presents a perpendicular line to the face of the stone when the joint is again tightened to prevent displacement. rlhe pick can then be operated by the raising and lowering of the hand of the operator, which grasps the bar K', the rear end of the bar K swiveling on the shaft to permit this motion, and also sliding ,along the shaft D to permit the necessary lateral movement of the pickin cracking the line over the face of the stone. To lessen the friction in sliding the picker along the shaft D the rear end of bar K is constructed with a frame, l?, into which rollers R are fitted and journaled, the edges of the rollers being' circularly grooved to iit the shaft D.

The instrument is placed upon the millstone in such a position that the shaft D is parallel to one of the leading furrows. The pickis then fed forward and a line cracked parallel to the leadin g furrow. It is then fed forward again and a second line cracked parallel to the first, and so on for any number of cracks. In this way all the lines will be straight and parallel to each. other, and no skilled labor is required to accomplish the work.

I claim as my invention- In combination with the herein-described handle of a millstonc-pick, composed of the bars K K', and adjusting joint M N, the roller-frame l) l?, operating in the manner and for the purposes set forth.

In testimony of which invention I have hereunto set my hand.

STEPHEN A. BELL.

Witnesses ELrTr-IA F. LAYMAN, FRANK MILLwARD. (57) 

